COMPLIANCE INFO - Laserfiche WebLink

Home Browse Search

Facility and PBR Units Closure Work Plan 1848 and 1856 Field Ave.,Stockton, California r The results of chemical analysis of these six soil samples are presented in the Characterization Summary. These results do not indicate evidence of a release. Samples were analyzed primarily for copper,the chemical ` considered the best indicator of a potential release due to its relative immobility. Copper levels in the soil samples ranged between 4.6 milligrams per kilogram(mg/kg)and 38 mg/kg.Copper was present at 79 mg/kg ` in the concrete sample,potentially normal depending on the source of the aggregate and cement.No volatile organic chemicals(VOCs)were detected at the only PBR unit location tested for VOCs(Location 14). r 2.2.2 Former Chemical Storage Tanks Three cross-linked polyethylene chemical storage tanks were formerly outside 1848 Field Avenue,near the western wall of the building.From north to south,the tanks were used for storage of hydrochloric acid,spent copper etch solution (cupric chloride with hydrochloric acid) and an aqueous solution of sodium chlorate r, known as "liquid chlorate replenishment (LCR)". In order to evaluate the potential for releases from these tanks, Earth Tech planned to collect one soil sample from beneath each of the three tanks. During sample collection in December 2001, Earth Tech discovered that the material beneath the concrete secondary containment walls and floor was a sand layer approximately 6 to 8 inches thick underlain by a plastic liner.In ` order not to damage the liner and thus prevent its reuse, Earth Tech chose to sample the sand inside this containment system, instead of the underlying soil. Subsequent discussions with the former facility environmental manager,Lloyd Finley,indicated that the liner and sand layer is continuous beneath all three tanks. Sand sample BLI-11 (shown on figures as Location 11)was collected from the sand in the containment liner under the LCR tank. Sand sample BLI-12(shown on figures as Location 12)was collected from the sand in the containment liner under the spent copper etch tank. Sand sample BL1-13 (shown on figures as Location 13)was collected from the sand in the containment liner under the hydrochloric acid tank. The results of chemical analysis of these three sand samples are presented in the Characterization Summary. pH levels of 9.8 and 9.3 were detected at sample Locations 11 and 13,respectively,while 350 mg/kg of copper was detected at Location 12.However,these results are inconclusive with respect to whether or not a release .. occurred at this location,because the material sampled was within the containment system,the samples may have been contaminated with concrete dust(the samples were collected after coring through the concrete and LJWORK1690991GeneraRField WPReldAw WPAug03r"2.doc 5 August2003